Maybe I really don't understand.
You don't and here's why :
"It can also be done with just events" is not a viable argument. There is a large library of well-known patterns written in BulletML on the internet. The point is to make these available for use in Construct 2.
It's a perfectly viable argument. I'm not saying to replace the xml file with events but the actual "translation" of those files which is what a plugin supposedly would do. And that's where you are missing the point of ALL my answers so far !
I see no reason why it would be impossible to have a plugin read a pattern file and execute it. E.g. the Unity wrapper does just that.
Helicopter vs car.
Unity is not C2, it's not designed and built the same way.
So what works in one does not necessary works in the other as well.
And see the next answer for further reasons...
It can obviously be done in JavaScript, as evidenced by the bulletml.js demos. C2 is also JS-based. The C2 engine and modern browsers can handle hundreds of objects without breaking a sweat. (Though some of the more advanced patterns need to handle thousands of on-screen bullets, which would require optimization out of scope of a plugin.)
A C2 plugin still relies on the objects in a C2 project. Your plugin won't magically spawn thousands of sprite objects from the void. Especially if you want after to handle their collisions or keep some handling on those objects.
So even if C2 plugins are indeed written in JavaScript, it's not because there is some JS SDK of some feature that it can necessary be turned into a C2 plugin.
And that's why the reading/translating of the xml file should rather be done in events, as mentioned already times and times again in Newt's and my posts.
So strangely enough, a few posts ago when I mentioned you had no clue/did not understand what you were asking, seems I was right. And all along I took the time to answer your questions and try to help/educate you while all you were doing was insulting me and this community, rambling about things you did not get in the first place.
I'm done as well. Enough time lost, enough energy spent.